Drill chuck



Feb 28; 1928.

S V. SEARS DRILL CHUCK Filed Aug. 1, 1927 Patented Feb. 28, 192 8.

UNITED STATES PATENT OFFICE.

Application filed August 1, 1981- Serial No. 210,163.

This invention is a rotary drill -chuck for churn drills, such as are used In drlllmg for oil, gas or water; and the ob ect of the invention is to provide a drill chuck which 6 will be caused automatically and intermittently to rotate or to partially rotate upon its longitudinal axis at each upward movement of the chuck, thereby causing of course a corresponding rotative movement of the drill mounted in the chuck.

In the drawing:

Figure 1 is an elevation of the chuck with attached drill and cable;

Figure 2 is a longitudinal section;

Figure 3 is a medial transverse section through the chuck,

Figure 4 is a detail of the cylindrical sleeve;

Figure 5 is a'detail of the twist pawl;

Figure 6 is a detail of the lock pawl.

This invention comprises an inner cylindrical sleeve 1 and an outer protective casing 25, the latter being provided with screw caps 26 and 27 Inasmuch as in operation, the end 26 of the casing and the corresponding end of the enclosed sleeve 1. are disposed downwardly, they will be referred to herein as the lower ends, and the opposite ends as the u 7 per ends thereof. The shank 2 of the drill 3 has a threaded engagement with the lower cap 26, as shown. A plurality of obliquely formed twist pawl slots 5 are formed through the wall of the upper end of the sleeve 1, these slots curving around the wall of the sleeve from their lower ends 6 to their upper ends 7 at angles of. approximately 45 degrees, more or less, relative to the longitudinal surface lines on the wall of the sleeve made by planes coincident with the longitudinal axis of the sleeve, as these planespass out throu h the wall of the sleeve. In actual use, it is found that four of these slots may .beemployed to advantage, but a greater or less number may be used as found best in any particular case, or in adapting the device to any particular use. Likewise the angularity of the slots may be modified as thought desirable. The lower or inner edges of the upper or outer ends of the slots 5 are cut away erpendicular to the said long1tud1nal surace lines soas to form pawl depressing edges 8. A solid, cylindrical pawl block 9 1s provided, the same being substantially shorter than the length of the cylinder 1, so as to play back and forth therein, and is mounted slidingly within the sleeve 1; the said block having a pawl slot 10 cut longitudinally and radially thereinto. An elongated twist pawl .11 is mounted loosely within this slot, being pivoted therein at. its lower end 12 by a pin 13 passed through the block 9 at the lower end of the slot 10, and loosely through the said pawl. Theupper end of the pawl 11 is formed with an outstanding lip 14 having a straight upper edge 15 standing per-v pendicular to the body of the block 9, and a beveled lower edge 16. A spring 17 set in the slot 10 back of the pawl 11 serves normally to force the lip 14 outwardly, although the lip may be forced inwardly under pressure, and flush with the bod of the block 9.

Similarly a lock pawl 23 aving a downwardly turned beveled lip 24, is pivotally mounted within the slot 10 upon the pin 13 alongside the twist pawl 11, and the nose 0 this pawl 23 is likewise normally proiected outwardly by a spring 22. An operating pin 18 is anchored inthe upper end of the block 9 and extends slidingly out through the cap 27. This pin is rovided with an eye 19 into which is secure the lower end of the operating cable (not shown). The cap 27 is provided with an extension 28, and a telescoping hood 29 is secured at 30 to the pin 18,. and enveloping the extension 28 serves to exclude dirt from the sleeve 1 and the working elements contained therein.

Through thewall of the sleeve 1, and immediately below and in longitudinal alignment with the'pawl depressing edges 8 at the upper ends of the several pawl slots 5, are formed an equal number of lock pawl slots 21, the same 'being formed parallel to the axis of the sleeve 1. The arrangement is such that the nose of the pawl 23 will snap laterally into the upper end of its registering lock pawl slot 21 as the pawl block 9 travels, with a lateral rotative or torsional movement to the upper'end of the sleeve 1 being turned simultaneously within the sa1 sleeve through the stated sliding engagement of the twist pawl 11 in the obllque slots 5. But the lower ends of the slots 21 fall short of the lowermost limit of travel of the pawl.

23, so that upon the downward travel of the pawl block 9 the bevel lip 24 of the pawl 23 enables the pawl 23 to ride out of the slot 21 in which it has been moving, and u on twist pawl 11 when the pawl block 9 is released by the impact of the blow of the downward stroke of the drill.

In the operation of the device, on the down stroke of the drill 3 and as the drill strikes the bottom of the well, the cable will of course be relaxed, and the weight of the block 9 will be sutficient to force the beveled edge 16 of the pawl 11 down upon one of the pawl depressing edges 8 at the upper end of one of the slots 5, thereby forcing the'pawl 11 inwardly and allowing the pawl block 9 to fall to the bottom of the sleeve 1. At this oint the pawl becomes aligned with the Power end of another one of the slots 5 and the lip 14 springs out into that slot. Then upon the upward movement again of the cable, the upper edge 15 of the lip 14 engages the upper oblique edge of the slot 5 in which it happens to be traveling, and the weight of the drill 3 is suflicient to pull the sleeve 1 downwardly against the lip 14 0f the pawl 11, and as the said lip 14 is thus forced upwardly along the one of the said oblique slots 5 in which it happens to be located, the chuck and drill are thereby caused to partially rotate. A like partial rotation of the chuck and drill is caused at each up and down movement of the cable. The lowermost or right hand margins of the sleeve 1 bordering on the slots 5 may be serrated as shown in Figure 4, for the purpose of catching the beveled edge 16 of the pawl 11 and thereby forcing the pawl 11 inwardly in the same way as intended by the pawl depressin edges 8, in case the pawl 11 should happen or any reason to miss one of the said pawl depressing edges 8 in the operation of the device.

While I have herein described a certain specific manner and method of constructing and assembling the elements of my invention, it is understood that I may vary from the same in minor details, not departing from the spirit of my invention, so as best to construct a practical device for the purpose intended, as defined in, the appended claims.

I claim:

1. A device of the kind described, comprising a cylindrical sleeve having means at one end for engaging the shank of a Well drill, the opposite end of the sleeve having 11 plurality of oblique pawl slots formed through the wall thereof; a cylindrical pawl block slidingly mounted wlthin the said sleeve, and the said pawl block being substantially shorter than the sleeve, and havmg a pawl slot cut longitudinally and radially therein; a spring set twist pawl pivotally mounted within the said pawl slot, the said pawl being formed and adapted upon the movement of the pawl block towards the slotted end of the said sleeve to engage one of the said oblique slots and rotate the pawl block relative to the sleeve, and upon the return movement of the said block to press inwardly and pass longitudinally into another one of the said oblique slots.

2. A device of the kind described, comprising a sleeve adapted at one end to en gage the shank of a well drill, the opposite end having a plurality of oblique pawl slots formed through the wall thereo the inwardly disposed edges of the outer ends of the slots being cut away to form pawl depressing edges; a relatively short cylindrical pawl block slidingly mounted within the said sleeve, the said pawl block having a pawl slot cut therein; and a spring set twist pawl pivotally mounted within the said pawl slot and adapted to retract --within its slot upon the inward movement of thesaid pawl block so as to permit the pawl block to move longitudinally within the sleeve, but adapted to expand and engage one of the said pawl slots upon the outward movement of the said pawl block, so"as to cause the pawl block and sleeve to partially rotate relative to each other. V 3. A device of the kind described, comprising a cylindrical sleeve having means at one end for engaging the shank of a well drill, the opposite end of the sleeve havin a plurality of oblique pawl slots formed through the wall thereof; a cylindrical pawl block slidingly mounted within the said sleeve, the said pawl block being substantially shorter than the sleeve, and having a pawl slot cut longitudinally and radially therein a spring set twist pawl pivotally mounted within the said pawl slot, the said pawl being formed and adapted upon the movement of the pawl block towards the slotted end of the said sleeve to engage one of the said oblique slots and rotate the pawl block relative to the sleeve, and upon the return movement of the said block to press inwardly and pass longitudinally into another one of the said oblique slots; and means for preventing a reverse rotation of the pawl block relative to the sleeve upon the return longitudinal movement of the pawl block.

4. In a device of the kind described, a cylindrical sleeve having a lurality of oblique twist pawl slots forme through its wall at one end and a like. number of straight lock pawl slots formed through its wall below and longitudinally aligned with the upper ends of the twist awl slots; a pawl block slidingly mounte within the sleeve, the said block being provided with a 5 twist pawl for engaging the twist pawl slots to cause a relatlve rotative movement of the block upon the travel of the block towards the end of the sleeve carrying the twist pawl slots, and with a lock pawl for engaging the lock pawl slots to prevent rela- 10 tive rotative movement of the pawl block: upon the return travel of the block. I

SAMUEL V. SEARS. 

